kll_sketch_get_n_double
Returns the number of items collected in the KLL double sketch.
Syntax
Python
from pyspark.sql import functions as sf
sf.kll_sketch_get_n_double(col)
Parameters
Parameter | Type | Description |
|---|---|---|
|
| The KLL double sketch binary representation. |
Returns
pyspark.sql.Column: The count of items in the sketch.
Examples
Example 1: Get count of items in KLL double sketch
Python
from pyspark.sql import functions as sf
df = spark.createDataFrame([1.0,2.0,3.0,4.0,5.0], "DOUBLE")
sketch_df = df.agg(sf.kll_sketch_agg_double("value").alias("sketch"))
sketch_df.select(sf.kll_sketch_get_n_double("sketch")).show()
Output
+-------------------------------+
|kll_sketch_get_n_double(sketch)|
+-------------------------------+
| 5|
+-------------------------------+